We talk more and more often aboutimportance of reducing the glycemic load meals to lose (or not gain) weight, but also to prevent numerous metabolic diseases, including diabetes. “The so-called glycemic index expresses the ability of the carbohydrates contained in a certain food to raise blood sugar”, explains Dr. Alberto Calabresenutrition biologist at Villa Lucia Hospital in Conversano, Bari. “To calculate it, the various foods are compared with glucose, the most important source of energy for humans, whose glycemic index is considered equal to 100. This means, for for example, that if a food has a glycemic index of 50 it will raise the blood sugar by half compared to what glucose would do ».
How low-glycemic foods work
The glycemic index of a food is determined by a series of factors, such as the chemical nature of the carbohydrates it contains and the simultaneous presence of other nutrients. “Think of milk: skim milk has a glycemic index of 32, while whole milk stops at 27. It might seem a paradox, given that the latter is richer in proteins, fats and fibers: instead, it is these macromolecules that slow down the absorption of sugars present in the drink, thanks to a particular biochemical mechanism that is activated in the intestine ».
A curiosity: with the same food, the glycemic index can vary from person to person: «In fact, what we find indicated in the nutritional tables is an average value established by the international scientific community, but the physiological and biochemical mechanisms are subjective due to an individual response to more or less sensitive glucose. Having said that, the variation can be of a few points, never so significant ».
They are considered low glycemic index foods such as yogurt, legumes (especially peas and beans), apples, nuts and milk. On the exact opposite of the fence, however, there are the foods with a high glycemic index (such as white bread, glucose syrup, honey, potatoes, almost all refined cereals, grapes, bananas and white rice), while those with an average value, around 40-60, are mainly wholemeal bread, wholemeal pasta al dente ( especially spaghetti), oranges and whole grains. “The same whole wheatthen, it can vary by several points, ranging from 45 to 55, depending on the fibers contained in the original flour. Not surprisingly, the advice is to favor a different grain than the traditional one, such as buckwheat or quinoa, both very rich in fiber ”, explains the expert.
How to regulate your diet
Obviously, it would be impossible to eat only low glycemic index foods. This is why the new trends seem to no longer take this parameter into account, referring rather to theinsulin index, or how much insulin production increases after eating. “To do so, therefore, the single food is not taken into consideration, but the meal as a whole. For example, to lower the insulin index, it is good to abandon the scheme of the dissociated diet, which involves the consumption of proteins in one meal, for example at dinner, and carbohydrates in the other meal, that is, at lunch “, suggests Calabrese.
«Together with bread and pasta, in fact, it is always advisable to combine a protein source. For example, pasta with tuna has a lower glycemic index than pasta with cherry tomatoes, because the tuna proteins modify the intestinal absorption parameters of the dish. Alternatively, we can combine the pasta with a green salad, because the fibers act the same way“.
Or, again, we can halve the normal amount of carbohydrates (40-50 grams), combine a slice of meat (70 grams) and add a side of vegetables (200 grams): “In this way, we not only lower the glycemic index carbohydrates, but we introduce multiple categories of macronutrients in the same meal, creating a sort of metabolic elasticitybecause the body has to activate different biochemical mechanisms to digest carbohydrates, proteins and fibers. In other words, the metabolism works harder“. An exception: combining pasta and legumes is not a valid alternative. «The latter, in fact, contain 50% carbohydrates, so they do not represent an effective source of protein as is often said. This means that a dish of pasta and beans increases the insulin index, it does not lower it ».
Drinking water yes, but it does not lower the insulin index
Often, on the web, it happens to read that hydrating abundantly during meals lowers the insulin index. “It’s about a fake newsbecause our blood has an extremely controlled pH, so we are unable to dilute it, except with special drugs », concludes Calabrese.
Perhaps, this association is inspired by diabetics, who drink often because they cannot eliminate glucose properly, so the body puts in place mechanisms – such as increased thirst – to dilute it in some way. «The same happens when we want to drink after eating an ice cream or something sweet: the body runs for cover to avoid a dangerous accumulation of sugar, which predisposes to atherosclerosis and thrombotic risks. But this has nothing to do with the glycemic index or the insulin index. Drinking remains a good daily habit, but it does not help us in this sense“.